using System;
using System.Collections.Generic;
using System.Text;
namespace Ch06ex01
{
    class Program
    {      
        static void Main(string[] args)
        {
            Console.WriteLine("{0} command line arguments were specified:",args.Length);
            foreach(string arg in args);//此处有问题 提示当前上下文中不存在arg         
            Console.WriteLine(arg);
            Console.ReadKey();
        }  
    }
}

编译有错 用的是命令行参数

现在关键是编译都通不过

最后问题解决
using System;
using System.Collections.Generic;
using System.Text;
namespace Ch06ex01
{
    class Program
    {      
        static void Main(string[] args)
        {
            Console.WriteLine("{0} command line arguments were specified:",args.Length);
            foreach(string arg in args)
           {
            Console.WriteLine(arg);
           }
            Console.ReadKey();
        }  
    }
}
foreach语句后面多了个分号 造成arg为被未声明的局部变量
最后谢谢各位的回答